Malaysia established the Joint Investigation Team (JIT) to investigate the incident, working with foreign aviation authorities and experts.[5]:1 Neither the crew nor the aircraft's communication systems relayed a distress signal, indications of bad weather, or technical problems before the aircraft vanished.[26] Two passengers travelling on stolen passports were initially suspect in the disappearance, but they were later determined to be asylum seekers and terrorism has been ruled out.[27][28][29] Malaysian police have identified the Captain as the prime suspect if human intervention was the cause of the disappearance, after clearing all other passengers of any suspicious motives.[30] Power was lost to the aircraft's satellite data unit (SDU) at some point between 01:07 and 02:03; the SDU logged onto Inmarsat's satellite communication network at 02:25—three minutes after the aircraft left the range of radar.[5]:22 Based on analysis of the satellite communications, the aircraft turned south after passing north of Sumatra and flew for five hours without communication and with little deviation in its track, suggesting that the aircraft was flying on autopilot without manual input from the cockpit and that Flight 370 may have experienced a hypoxia event, ending when fuel was exhausted.[5]:34[31][32][33]

At the time of its disappearance, and if the presumed loss of all on board is confirmed, Flight 370 was the deadliest aviation incident in Malaysia Airlines' history and the deadliest involving a Boeing 777.[34][35] It was surpassed in both regards 131 days later by the crash of another Malaysia Airlines Boeing 777 – Flight 17 – that was shot down over Ukraine.[36] Malaysia Airlines was struggling financially, a problem which was exacerbated by a decline in ticket sales after Flight 370 disappeared and before the crash of Flight 17; the airline was renationalised by the end of 2014. The Malaysian government received significant criticism, especially from China, for failing to disclose information in a timely manner during the early weeks of the search. Flight 370's disappearance brought to the public's attention the limits of aircraft tracking and flight recorders, including several issues raised four years earlier—but never mandated—following the loss of Air France Flight 447. A task force set up by the International Air Transport Association, with the support of the International Civil Aviation Organization, proposed a new standard that, by December 2015, commercial aircraft report their positions every 15 minutes.[37][38] The Malaysian Ministry of Transport issued an interim report on 8 March 2015.[39][40]

The planned flight duration was 5 hours, 34 minutes, which would consume an estimated 37,200 kg (82,000 lb) of jet A-1 fuel. The aircraft carried 49,100 kilograms (108,200 lb) of jet fuel, including reserves, which allowed an endurance of 7 hours, 31 minutes. The extra fuel was enough to divert to the first alternate airport Jinan Yaoqiang International Airport or the second alternate airport Hangzhou Xiaoshan International Airport, which would require 4,800 kg (10,600 lb) or 10,700 kg (23,600 lb), respectively, to reach from Beijing.[39]:1, 30

At 00:42, Flight 370 took off from runway 32R,[39]:1 and was cleared by air traffic control (ATC) to climb to flight level 180[c]—approximately 18,000 feet (5,500 m)—on a direct path to waypoint IGARI. Voice analysis determined that the First Officer communicated with ATC while the flight was on the ground and that the Captain communicated with ATC after departure.[39]:21 Shortly after departure, the flight was transferred from the airport's air traffic control to "Lumpur Radar" air traffic control on frequency 132.6 MHz. Air traffic control over peninsular Malaysia and adjacent waters is provided by the Kuala Lumpur Area Control Center (ACC); Lumpur Radar is the name of the frequency used for en route air traffic.[43] Lumpur Radar cleared Flight 370 to flight level 350[c]—approximately 35,000 ft (10,700 m). At 01:01, Flight 370's crew reported to Lumpur Radar that they had reached flight level 350, which they confirmed again at 01:08.[39]:1–2[44]

The crew was expected to contact air traffic control in Ho Chi Minh City as the aircraft passed into Vietnamese airspace, just north of the point where contact was lost.[49][50] The captain of another aircraft attempted to reach the crew of Flight 370 "just after [01:30]" using the international distress frequency to relay Vietnamese air traffic control's request for the crew to contact them; the captain said he was able to establish contact, but just heard "mumbling" and static.[51] Calls made to Flight 370's cockpit at 02:39 and 07:13 were unanswered but acknowledged by the aircraft's satellite data unit.[5]:18[46]:40

Data from Malaysian military radar showing Flight 370 (green) crossing the Strait of Malacca and Andaman Sea to where it was last seen by radar. The left of the two segments of the flight track follows air route N571 between waypoints VAMPI and MEKAR; the white circle appears to highlight a section where the aircraft was not tracked by radar.

At 01:20:31, Flight 370 was observed on radar at the Kuala Lumpur ACC as it passed the navigational waypoint IGARI (6°56′12″N103°35′6″E﻿ / ﻿6.93667°N 103.58500°E﻿ / 6.93667; 103.58500﻿ (Waypoint IGARI)) in the Gulf of Thailand and five seconds later, the Mode-S symbol disappeared from radar screens.[39]:2 At 01:21:13, Flight 370 disappeared from the radar screen at Kuala Lumpur ACC and was lost about the same time on radar at Ho Chi Minh ACC, which claims the aircraft was at the nearby waypoint BITOD.[39]:2[44] Air traffic control uses secondary radar, which relies on a signal emitted by a transponder on aircraft; therefore, after 01:21 the transponder on Flight 370 was no longer functioning. The final data from the transponder indicated the aircraft was flying at its assigned cruise altitude of flight level 350[c] and was travelling at 471 knots (872 km/h; 542 mph) true airspeed.[52] There were few clouds around this point and no rain or lightning nearby.[39]:33–36 Later analysis estimated that Flight 370 had 41,500 kg (91,500 lb) of fuel when it disappeared from secondary radar.[39]:30

At the time the transponder stopped functioning—01:21:13—military radar showed Flight 370 turning right, but almost immediately making a constant left turn to a south-westerly direction.[39]:3 From 01:30:35-01:35, military radar showed Flight 370 at 35,700 ft (10,900 m)[e] on a 231° magnetic heading, with a ground speed of 496 knots (919 km/h; 571 mph). Flight 370 continued across the Malay Peninsula, fluctuating between 31,000–33,000 ft (9,400–10,100 m) in altitude. At 01:52, Flight 370 was detected passing just south of Penang Island. From there, the aircraft flew across the Strait of Malacca to or close to the waypoint VAMPI, passing over Pulau Perak at 02:03, after which it flew along air route N571 to waypoints MEKAR, NILAM, and possibly IGOGU.[5]:3, 38 The last known location, from and near the limits of Malaysian military radar, was at 02:22, 10 nautical miles (19 km; 12 mi) north of waypoint MEKAR[39]:3, 7 and 200 nmi (370 km; 230 mi) northwest of Penang at an altitude of 29,500 ft (9,000 m).[53][54]

Because of the sensitive nature of revealing military radar capabilities, countries in the region where Flight 370 disappeared have been reluctant to release information they may have collected from military radar. Despite possibly flying near or over the northern tip of Sumatra,[44] Indonesia—which has an early warning radar system—has publicly denied sighting Flight 370 on radar after contact was lost, although the Indonesian military did track Flight 370 earlier when en route to waypoint IGARI.[39]:4[55] Thailand and Vietnam also detected Flight 370 on radar before the transponder stopped working, but not afterwards.[39]:4–5 No radar contact was detected by Australia, including the JORNover-the-horizon radar system, which was believed to be looking north to detect illegal migrants and not west over the Indian Ocean where Flight 370 is presumed to have flown based on satellite communications.[56]

At 02:25, the aircraft's satellite communication system sent a "log-on request" message—the first message on the system since the ACARS transmission at 01:07—which was relayed by satellite to a ground station, both operated by satellite telecommunications company Inmarsat. After logging on to the network, the satellite data unit aboard the aircraft responded to hourly status requests from Inmarsat and two ground-to-aircraft phone calls, at 02:39 and 07:13, which went unanswered by the cockpit.[5]:18[46] The final status request and aircraft acknowledgement occurred at 08:10. The aircraft sent a log-on request at 08:19:29 which was followed, after a response from the ground station, by a "log-on acknowledgement" message at 08:19:37. The log-on acknowledgement is the last piece of data available from Flight 370. The aircraft did not respond to a status request from Inmarsat at 09:15.[5][46][57][58]

Flight Information Regions in the vicinity of where Flight 370 disappeared from secondary radar. Kuala Lumpur ACC provides ATC services on two routes, located within FIR Singapore, between Malaysia and Vietnam. (Note: Air routes are depicted as roughly 5 nmi / 8–10 km wide, but vary in width, with some as wide as 20 nmi / 30–35 km.)

At 01:38, Ho Chi Minh Area Control Centre (ACC) contacted Kuala Lumpur Area Control Centre to query the whereabouts of Flight 370 and informed them that they had not established verbal contact with Flight 370, which was last detected by radar at waypoint BITOD. The two centres exchanged four more calls over the next 20 minutes with no new information.[44][59]

At 02:03, Kuala Lumpur ACC relayed to Ho Chi Minh ACC information received from Malaysia Airlines' operations centre that Flight 370 was in Cambodian airspace. Ho Chi Minh ACC contacted Kuala Lumpur ACC twice in the following eight minutes asking for confirmation that Flight 370 was in Cambodian airspace.[44] At 02:15, the watch supervisor at Kuala Lumpur ACC queried Malaysia Airlines' operations centre, which said that it could exchange signals with Flight 370 and that Flight 370 was in Cambodian airspace.[59] Kuala Lumpur ACC contacted Ho Chi Minh ACC to query that the planned flight path for Flight 370 passed through Cambodian airspace. Ho Chi Minh ACC responded that Flight 370 was not supposed to enter Cambodian airspace and that they had already contacted Phnom Penh ACC (which controls Cambodian airspace), which had no contact with Flight 370.[44] Kuala Lumpur ACC contacted Malaysia Airlines' operations centre at 02:34, inquiring about the communication status with Flight 370, and were informed that Flight 370 was in a normal condition based on a signal download and that it was located at 14°54′00″N109°15′00″E﻿ / ﻿14.90000°N 109.25000°E﻿ / 14.90000; 109.25000.[44][59] Later, another Malaysia Airlines aircraft, Flight 386 bound for Shanghai was requested by Ho Chi Minh ACC to attempt to contact Flight 370 on the Lumpur Radar frequency—the frequency on which Flight 370 last made contact with Malaysian air traffic control—and on emergency frequencies, but without success.[44][60]

At 03:30, Malaysia Airlines' operations centre informed Kuala Lumpur ACC that the locations it had provided earlier were "based on flight projection and not reliable for aircraft positioning."[44] Over the next hour, Kuala Lumpur ACC contacted Ho Chi Minh ACC asking whether they had contacted Chinese air traffic control. At 05:09, Singapore ACC was queried for information about Flight 370. At 05:20, an undisclosed official—identified in the preliminary report released by Malaysia as "Capt [name redacted]"—contacted Kuala Lumpur ACC requesting information about Flight 370; he opined that, based on known information, "MH370 never left Malaysian airspace."[44]

The watch supervisor at Kuala Lumpur ACC activated the Kuala Lumpur Aeronautical Rescue Coordination Centre (ARCC) at 05:30, over four hours after communication was lost with Flight 370.[59] The ARCC is a command post at an Area Control Centre that coordinates search-and-rescue activities when an aircraft is lost.

Malaysia Airlines issued a media statement at 07:24, one hour after the scheduled arrival time of the flight at Beijing, stating that contact with the flight had been lost by Malaysian ATC at 02:40 and that the government had initiated search and rescue operations;[61] the time when contact was lost was later corrected to 01:21.[62] Neither the crew nor the aircraft's communication systems relayed a distress signal, indications of bad weather, or technical problems before the aircraft vanished from radar screens.[26]

On 24 March, Malaysian Prime Minister Najib Razak appeared before media at 22:00 local time to give a short statement regarding Flight 370, during which he announced:

This evening I was briefed by representatives from the UK Air Accidents Investigation Branch. They informed me that Inmarsat, the UK company that provided the satellite data which indicated the northern and southern corridors, has been performing further calculations on the data. Using a type of analysis never before used in an investigation of this sort...Inmarsat and the AAIB have concluded that MH370 flew along the southern corridor, and that its last position was in the middle of the Indian Ocean, west of Perth. This is a remote location, far from any possible landing sites. It is therefore with deep sadness and regret that I must inform you that, according to this new data, flight MH370 ended in the southern Indian Ocean.[17]

Just before Najib spoke at 22:00 MYT, an emergency meeting was called in Beijing for relatives of Flight 370 passengers.[17] Malaysia Airlines announced that Flight 370 was assumed lost with no survivors. It notified most of the families in person or via telephone, and some received the following SMS (in English and Chinese):[17]

Malaysia Airlines deeply regrets that we have to assume beyond any reasonable doubt that MH370 has been lost and that none of those on board survived. As you will hear in the next hour from Malaysia's Prime Minister, we must now accept all evidence suggests the plane went down in the Southern Indian Ocean.[13][14][15]

We have concluded that the aircraft exhausted its fuel over a defined area of the southern Indian Ocean, and that the aircraft is located on the sea floor close to that defined area. This is a remote location, far from any possible landing sites. It is also an area with adverse sea conditions with known depths of more than 6,000 metres. After 327 days...and based on all available data as well as circumstances mentioned earlier, survivability in the defined area is highly unlikely....On behalf of the Government of Malaysia, we officially declare Malaysia Airlines flight MH370 an accident in accordance with the Standards of Annexes 12 and 13 to the Chicago Convention and that all 239 of the passengers and crew onboard MH370 are presumed to have lost their lives.[1]

If the official assumption is confirmed, at the time of its disappearance Flight 370 was the deadliest aviation incident in the history of Malaysia Airlines (surpassing the 1977 hijacking and crash of Malaysian Airline System Flight 653 that killed all 100 passengers and crew on board) and the deadliest involving a Boeing 777, surpassing Asiana Airlines Flight 214 (3 fatalities).[34][35] In both of those categories, Flight 370 was surpassed just 131 days later by Malaysia Airlines Flight 17, another Boeing 777-200ER, which was shot down on 17 July 2014, killing all 298 persons aboard.[36]

HCM ACC contacts Kuala Lumpur ACC (KL ACC) to inquire about Flight 370. HCM ACC tells them that verbal contact was not established and Flight 370 disappeared from its radar screens near BITOD waypoint. KL ACC responded that Flight 370 did not return to its frequency after passing waypoint IGARI.[39]:2[44]

01:05

01:46

17:46

HCM ACC contacts KL ACC again, inform them radar contact was established near IGARI, but lost near BITOD and that verbal contact was not established.[44]

01:16

01:57

17:57

HCM ACC informs KL ACC that there was no contact with Flight 370, despite attempts on many frequencies and aircraft in the vicinity.[44]

01:22

02:03

18:03

Malaysia Airlines dispatch center sent a message to the cockpit instructing pilots to contact Vietnam ATC, which was not responded to.[64] A ground-to-aircraft ACARS data request, transmitted from the ground station multiple times between 02:03-02:05, was not acknowledged by the aircraft's satellite data unit.[46]:36–39

KL ACC queries Malaysia Airlines' operations center, which replies that it is able to exchange signals with flight which is in Cambodian airspace.[44]

01:37

02:18

18:18

KL ACC contacts HCM ACC asking them if Flight 370 was supposed to enter Cambodian airspace. HCM ACC replies that Flight 370's planned route did not take it into Cambodian airspace and that they had checked and Cambodia had no information or contact with Flight 370.[44]

"Log-on request" sent by aircraft to satellite. Satellite communication link is reestablished after being lost for between 22–68 min.[5]:18[46]:39 Sometimes referred to as the first hourly "handshake" after disappearing from radar.[57][65]

01:53

02:34

18:34

KL ACC queries Malaysia Airlines' operations centre about communication status with Flight 370, but it was not sure if a message sent to Flight 370 was successful or not.[44]

Malaysia Airlines' operations centre informs KL ACC that position information was based on flight projection and not reliable for aircraft tracking. Between 03:30 and 04:25, KL and HCM ACCs query Chinese air traffic control.[44]

Sixth and last successful automated hourly handshake with Inmarsat-3 F1[57][66]

00:11

07:38

08:19:29

00:19:29

"Log-on request" sent by aircraft to satellite (sometimes referred to as a "partial handshake")[67][68] believed to have occurred when emergency power restarted the SDU shortly after fuel exhaustion and loss of power.[5]:18, 33[46]:41

07:38

08:19:37

00:19:37

After the ground station responded to the log-on request, the aircraft replied with a "log-on acknowledgement" transmission at 08:19:37.443. This is the last transmission received from Flight 370.[5]:18[46]:41

08:34

09:15

01:15

Aircraft did not respond to a scheduled, hourly handshake attempt by Inmarsat.[46]:41[57]

A search and rescue effort was launched soon after the aircraft's disappearance in Southeast Asia, but the following week, analysis of satellite communications between the aircraft and a communications satellite determined that the aircraft had continued flying for several hours and the final transmission from the aircraft was made over the Southern Indian Ocean, west of Australia. The surface search in the southern Indian Ocean between 18 March and 28 April searched over 4,600,000 square kilometres (1,800,000 sq mi) and involved 19 vessels and 345 search sorties by military aircraft.[69] The current phase of the search is a bathymetric survey and sonar search of the seafloor, about 1,800 kilometres (1,100 mi) southwest of Perth, Australia.[18]

The search for Flight 370 is the most expensive search operation in aviation history,[21][22][70][71] but has failed to locate any physical debris from the aircraft.[25] In June 2014, Time estimated that the total search effort to that point had cost approximately US$70 million.[72] The tender for the underwater search is AU$52 million (US$43 million or €35 million)—shared by Australia and Malaysia—for 12 months, but would differ if found in more or less time.[19]

Since 30 March 2014, the search has been coordinated by the Joint Agency Coordination Centre (JACC), an Australian government agency established specifically to co-ordinate the search effort to locate and recover Flight 370, which primarily involves the Malaysian, Chinese, and Australian governments.[73]

The Kuala Lumpur Aeronautical Rescue Coordination Centre (ARCC) was activated at 05:30—four hours after communication was lost with Flight 370—to co-ordinate search and rescue efforts.[59] Search efforts began in the Gulf of Thailand and South China Sea. On the second day of the search, Malaysian officials revealed that radar recordings indicated Flight 370 may have turned around; the search zone was expanded to include part of the Strait of Malacca.[74] On 12 March, the chief of the Royal Malaysian Air Force announced that an unidentified aircraft—believed to be Flight 370—had travelled across the Malay peninsula and was last sighted on military radar 370 km (200 nmi; 230 mi) northwest of Penang Island; search efforts were subsequently increased in the Andaman Sea and Bay of Bengal.[54]

Records of signals sent between the aircraft and a communications satellite over the Indian Ocean revealed that the aircraft had continued flying for almost six hours after its final sighting on Malaysian military radar. Initial analysis of these communications determined that Flight 370 was along one of two arcs—equidistant from the satellite—when its last signal was sent; the same day this analysis was publicly disclosed, 15 March, authorities announced they would abandon search efforts in the South China Sea, Gulf of Thailand, and Strait of Malacca to focus their efforts on the two corridors. The northern arc—from northern Thailand to Kazakhstan—was soon discounted as the aircraft would have to pass through heavily militarised airspace and those countries claimed their military radar would have detected an unidentified aircraft entering their airspace.[75][76][77]

The shifting search zones for Flight 370 in the Southern Indian Ocean. The inset shows the path of taken by the vessel ADV Ocean Shield operating a towed pinger locator, acoustic detections, and the sonar search. The current underwater phase (both the wide area search and priority area) is shown in pink.

The focus of the search shifted to the Southern Indian Ocean west of Australia and within Australia's concurrent aeronautical and maritime Search and Rescue regions that extend to 75°E longitude.[78][79] Accordingly, on 17 March, Australia agreed to lead the search in the southern locus from Sumatra to the southern Indian Ocean.[16][80]

From 18–27 March, the search effort focused on a 305,000 km2 (118,000 sq mi) area about 2,600 km (1,600 mi) south-west of Perth[81] that Australian Prime Minister Tony Abbott said is "as close to nowhere as it's possible to be" and which is renowned for its strong winds, inhospitable climate, hostile seas, and deep ocean floors.[82][83] Satellite imagery of the region was analysed; several objects of interest and two possible debris fields were identified on images captured between 16–26 March. None of these possible objects were found by aircraft or ships.[84]

Revised estimates of the radar track and the aircraft's remaining fuel led to a move of the search 1,100 km (680 mi) north-east of the previous area on 28 March[85][86][87] which was followed by another shift on 4 April.[88][89] An intense effort began to locate the underwater locator beacons (ULBs; informally known as "pingers") attached to the aircraft's flight recorders, whose batteries were expected to expire around 7 April.[90][91] Two ships equipped with towed pinger locators (TPLs) and a submarine equipped with a hull-mounted acoustic system,[5]:11–12 began searching for pings along a 240-kilometre (150 mi) seabed line believed to be the Flight 370 impact area.[90][92][93] Operators considered it a shot in the dark,[94] when comparing the vast search area with the fact that a TPL could only search up to 130 km2 (50 sq mi) per day.[94] Between 4–8 April several acoustic detections were made that were close to the frequency and rhythm of the sound emitted by the flight recorders' ULBs; analysis of the acoustic detections determined that, although unlikely, the detections could have come from a damaged ULB.[5]:13 A sonar search of the seafloor near the detections was carried out between 14 April and 28 May without any sign of Flight 370.[5]:14 It was later revealed that the battery for the ULB attached to Flight 370's flight data recorder expired in December 2012 and may not have been as capable.[95][96]

In late June, details of the next phase of the search were announced;[97] officials have called this phase the "underwater search", despite the previous seafloor sonar survey.[20] Continued refinement of analysis of Flight 370's satellite communications identified a "wide area search" along the arc where Flight 370 was located when it last communicated with the satellite. The priority search area within the wide area search is in its southern extent.[98] Some of the equipment to be used for the underwater search operates best when towed 200 m (650 ft) above the seafloor and is towed at the end of a 10 km (6 mi) cable.[99] Available bathymetric data for this region was of poor resolution, thus necessitating a bathymetric survey of the search area before the underwater phase began.[100] Commencing in May, the bathymetric survey charted around 208,000 square kilometres (80,000 sq mi) of seafloor through 17 December 2014, when it was suspended for the ship conducting the survey to be mobilised in the underwater search.[101]

The underwater phase of the search, which began on 6 October 2014,[98] uses three vessels equipped with towed deep water vehicles, which use side-scan sonar, multi-beam echo sounders, and video cameras to locate and identify aircraft debris.[102] A fourth vessel joined the search at the end of January 2015; it has an autonomous underwater vehicle (AUV) which can search areas which cannot be effectively searched by equipment on the other vessels.[103][104] As of 18 March 2015, over 30,000 square kilometres (12,000 sq mi)[105] of seafloor has been searched, which is about 50 percent of the priority search area; with no significant delays, the search of the priority search area will be completed around May 2015.[106]

Flight 370 was operated with a Boeing 777-2H6ER,[f]serial number 28420, registration 9M-MRO. The 404th Boeing 777 produced,[108] it first flew on 14 May 2002 and was delivered new to Malaysia Airlines on 31 May 2002. The aircraft was powered by two Rolls-Royce Trent 892 engines[108] and configured to carry 282 passengers.[109] It had accumulated 53,471.6 hours and 7,526 cycles in service[39]:22 and had not previously been involved in any major incidents,[110] though a minor incident while taxiing at Shanghai Pudong International Airport in August 2012 resulted in a broken wingtip.[111][112] Its last maintenance "A check" was carried out on 23 February 2014.[113] The aircraft was in compliance with all applicable Airworthiness Directives for the airframe and engines.[39]:27 A replenishment of the crew oxygen system—a routine maintenance task—was performed on 7 March 2014; an examination of this procedure found nothing unusual.[39]:27

Malaysia Airlines released the names and nationalities of the 227 passengers and 12 crew members, based on the flight manifest, later modified to include two Iranian passengers travelling on stolen passports.[119]

All 12 crew members were Malaysian citizens. Two pilots were among the crew:[120]

The pilot in command was 53-year-old Captain Zaharie Ahmad Shah from Penang. He joined Malaysia Airlines as a cadet pilot in 1981 and, after training and receiving his commercial pilot's license, became a Second Officer with the airline in 1983. Captain Shah was promoted to captain of the Boeing 737-400 in 1991, captain of Airbus A330-300 in 1996, and to captain of Boeing 777-200 in 1998. He had been a Type Rating Instructor and Type Rating Examiner since 2007 and had 18,365 hours of flying experience.[39]:13[120][121]

The co-pilot was 27-year-old First Officer Fariq Abdul Hamid. He joined Malaysia Airlines as a cadet pilot in 2007 and became a Second Officer on Boeing 737-400 aircraft. He was promoted to first officer of Boeing 737-400 aircraft in 2010 and later transitioned to Airbus A330-300 aircraft in 2012. In November 2013, he began training as first officer on Boeing 777-200 aircraft. Flight 370 was his final training flight and he was scheduled to be examined on his next flight. Hamid had 2,763 hours of flying experience.[39]:14[122][123]

Of the 227 passengers, 152 were Chinese citizens, including a group of 19 artists with 6 family members and 4 staff returning from a calligraphy exhibition of their work in Kuala Lumpur; 38 passengers were Malaysian. The remaining passengers were from 13 different countries.[124] Twenty passengers — 12 of whom were from Malaysia and 8 from China — were employees of Freescale Semiconductor.[125][126]

Under a 2007 agreement with Malaysia Airlines, Tzu Chi – an international Buddhist organisation – immediately sent specially trained teams to Beijing and Malaysia to give emotional support to passengers' families.[127][128] The airline also sent its own team of caregivers and volunteers[129] and agreed to bear the expenses of bringing family members of the passengers to Kuala Lumpur and providing them with accommodation, medical care, and counselling.[130] Altogether, 115 family members of the Chinese passengers flew to Kuala Lumpur.[131] Some other family members chose to remain in China, fearing they would feel too isolated in Malaysia.[132]

Malaysia set up a Joint Investigation Team (JIT), composed of specialists from Malaysia, Australia, China, the UK, the US, and France,[5]:1[133] being led according to the ICAO standards by "an independent investigator in charge".[134][135][136] The team consists of an airworthiness group, an operations group, and a medical and human factors group. The airworthiness group will examine issues related to maintenance records, structures, and systems of the aircraft. The operations group will review flight recorders, operations, and meteorology. The medical and human factors group will investigate psychological, pathological, and survival factors.[137] Malaysia also announced, on 6 April, that it had set up three ministerial committees—a Next of Kin Committee, a committee to organise the formation of the Joint Investigation Team, and a committee responsible for Malaysian assets deployed in the search effort.[137] The criminal investigation is being led by the Royal Malaysia Police,[1]:9 assisted by Interpol and other relevant international law enforcement authorities.[138][139]

The Malaysian Ministry of Transport issued an interim report entitled "Factual Information: Safety Information for MH370" on 8 March 2015. As suggested by the report's title, it focused on providing factual information and not analysis of possible causes of the disappearance.[142]

The communications between Flight 370 and the satellite communication network operated by Inmarsat, which were relayed by the Inmarsat-3 F1 satellite, provide the only significant clues to the location of Flight 370 after disappearing from Malaysian military radar at 02:22. These communications have also been used to deduce possible in-flight events (see next section). The investigative team was challenged with reconstructing the flight path of Flight 370 from a limited set of transmissions with no explicit location information about the aircraft's location, heading, or speed.[5]:16–17[65]

A depiction of an Inmarsat-3 series satellite. Flight 370 was in contact with Inmarsat-3 F1 (also known as "IOR" for Indian Ocean Region).

Aeronautical satellite communication (SATCOM) systems are used to transmit messages from the aircraft cockpit as well as automated messages from on-board systems using the ACARS communications protocol, but may also be used to transmit FANS and ATN messages and provide voice, fax and data links[143] using other protocols.[65][144][145] The aircraft's satellite data unit (SDU) is used to send and receive signals with the satellite communications network; it operates independently of other aircraft equipment which communicate through the SATCOM system, many using the ACARS protocol. Signals from the SDU are relayed by a satellite, which simply changes the signal's frequency, and then received by a ground station which processes the signal and, if applicable, routes it to its destination (e.g.. Malaysia Airline's operations centre); signals to the aircraft are sent in reverse order. When the SDU is powered on and attempts to connect with the Inmarsat network, it will transmit a log-on request, which the ground station acknowledges.[5]:17[145] This is, in part, to determine that the SDU belongs to an active service subscriber and also used to determine which satellite should be used to transmit messages to the SDU.[145] After connecting, if a ground station has not received any contact from a terminal for one hour,[j] the ground station will transmit a "log-on interrogation" message—informally referred to as a "ping";[5]:18 an active terminal automatically responds. The entire process of interrogating the terminal is referred to as a 'handshake'.[57][146]

Although the ACARS data link on Flight 370 stopped functioning between 01:07 and 02:03 MYT,[46]:36 the SDU remained operable.[5] After last contact by primary radar west of Malaysia, the following records were recorded in the log of Inmarsat's ground station at Perth, Western Australia (all times MYT/UTC+8):[5]:18[46][k]

A few deductions can be made from the satellite communications. The first is that the aircraft remained operational until at least 08:19—seven hours after final contact was made with air traffic control over the South China Sea. The varying burst frequency offset (BFO) values indicate the aircraft was moving at speed. The aircraft's SDU needs location and track information to keep its antenna pointed towards the satellite, so it can also be deduced that the aircraft's navigation system was operational.[147]:4

Since the aircraft did not respond to a ping at 09:15, it can be concluded that at some point between 08:19 and 09:15, the aircraft lost the ability to communicate with the ground station.[57][58][146] The log-on message sent from the aircraft at 08:19:29 was "log-on request".[5]:22 There are only a few reasons the SDU would transmit a log-on request, such as a power interruption, software failure, loss of critical systems providing input to the SDU, or a loss of the link due to the aircraft's attitude.[5]:22 Investigators consider the most likely reason to be that they were sent during power-up after an electrical outage.[5]:33 At 08:19, the aircraft had been airborne for 7 h 38 min; the typical Kuala Lumpur-Beijing flight is 51⁄2 hours and fuel exhaustion was likely.[5]:33[5]:33[148] In the event of fuel exhaustion and engine flame-out—which would eliminate power to the SDU—the aircraft's ram air turbine would deploy, providing power to some instruments and flight controls, including the SDU.[5]:33 Approximately 90 seconds after the 02:25 handshake—also a log-on request—communications from the aircraft's inflight entertainment system were recorded in the ground station log. Similar messages would be expected following the 08:19 handshake but none were received, supporting the fuel starvation scenario.[5]:22

Two parameters associated with these transmissions that were recorded in a log at the ground station were key to the investigation:

Burst time offset (BTO) — the time difference between when a signal is sent from the ground station and when the response is received. This measure is twice the distance from the ground station to satellite to the aircraft and includes the time that the SDU takes between receiving and responding to the message and time between reception and processing at the ground station. This measure can be analysed to determine the distance between the satellite and the aircraft and results in a ring on the Earth's surface that is equidistant from the satellite at the calculated distance, which can be reduced to arcs by eliminating parts of the rings outside the aircraft's range.[5]:18[147]:4–6

Burst frequency offset (BFO) — the difference between the expected and received frequency of transmissions. The difference is caused by Doppler shift as the signals travelled from the aircraft to the satellite to the ground station; the frequency translations made in the satellite and at the ground station; a small, constant error (bias) in the SDU that results from drift and ageing; and compensation applied by the SDU to counter the Doppler shift on the uplink. This measure can be analysed to determine the aircraft's speed and heading, but multiple combinations of speed and heading can be valid solutions.[5]:18[147]:9–11

By combining the distance between the aircraft and satellite, speed, and heading with aircraft performance constraints (e.g. fuel consumption, possible speeds and altitudes), investigators generated candidate paths that were analysed separately by two methods. The first assumes the aircraft was flying on one of the three autopilot modes (two are further affected by whether the navigation system used magnetic north or true north as a reference) and calculates the BTO and BFO values along these routes and compares them with the values recorded from Flight 370. The second method generated paths which had the aircraft's speed and heading adjusted at the time of each handshake to minimise the difference between the calculated BFO of the path and the values recorded from Flight 370.[5]:18, 25–28[149]:10–11 A probability distribution for each method at the BTO arc of the sixth handshake of the two methods was created and then compared; 80 percent of the highest probability paths for both analyses combined intersect the BTO arc of the sixth handshake between 32.5°S and 38.1°S, which can be extrapolated to 33.5°S and 38.3°S along the BTO arc of the seventh handshake.[149]:12

The SATCOM link functioned normally from pre-flight (beginning at 00:00 MYT) until it responded to a ground-to-air ACARS message with an acknowledge message at 01:07. Ground-to-air ACARS messages continued to be transmitted to Flight 370 until Inmarsat's network sent multiple "Request for Acknowledge" messages at 02:03, without a response from the aircraft. At some time between 01:07 and 02:03, power was lost to the SDU. At 02:25, the aircraft's SDU sent a "log-on request".[5]:22[46]:36–39 It is not common for a log-on request to be made in-flight, but it could occur for multiple reasons. An analysis of the characteristics and timing of these requests suggest a power interruption in-flight is the most likely culprit.[5]:33[150] As the power interruption was not due to engine flame-out, per ATSB, it may have been the result of manually switching off the aircraft's electrical system.[5]:33

An analysis by the ATSB comparing the evidence available for Flight 370 with three categories of accidents—an in-flight upset (e.g., stall), a glide event (e.g., engine failure, fuel starvation), and an unresponsive crew or hypoxia event—concluded that an unresponsive crew or hypoxia event "best fit the available evidence"[5]:34 for the five-hour period of the flight as it travelled south over the Indian Ocean without communication or significant deviations in its track,[5]:34 likely on autopilot.[31][32][33] There is no consensus among investigators on the unresponsive crew or hypoxia theory.[31]

Two men identified on the passenger manifest, an Austrian and an Italian, had reported their passports stolen in 2012 and 2013, respectively.[26][151] Interpol stated that both passports were listed on its database of lost and stolen passports, and that no check had been made against its database.[152][153] Malaysia's Home Minister, Ahmad Zahid Hamidi, criticised his country's immigration officials for failing to stop the passengers travelling on the stolen European passports.[153] The two one-way tickets purchased for the holders of the stolen passports were booked through China Southern Airlines.[154] It was reported that an Iranian had ordered the cheapest tickets to Europe via telephone in Bangkok, Thailand. The tickets were paid for in cash.[155][156] The two passengers were later identified as Iranian men, one aged 19 and the other 29, who had entered Malaysia on 28 February using valid Iranian passports. The head of Interpol said the organisation was "inclined to conclude that it was not a terrorist incident".[27] The two men were believed to be asylum seekers.[28][29]

United States and Malaysian officials were reviewing the backgrounds of every passenger named on the manifest.[124] On 18 March, the Chinese government announced that it had checked all of the Chinese citizens on the aircraft and ruled out the possibility that any were potential hijackers.[157]

One passenger who worked as a flight engineer for a Swiss jet charter company was briefly suspected as a potential hijacker because he was thought to have the relevant skill set.[158]

Police searched the homes of the pilot and co-pilot,[159] on suspicion that those in the cockpit had been responsible for the aircraft's disappearance.[160] The United States' Federal Bureau of Investigation reconstructed the deleted data from the pilot's home flight simulator and a Malaysian government spokesman indicated that "nothing sinister" had been found on it.[161][162] On 2 April, Khalid Abu Bakar, Malaysia's Police Inspector-General, said that as part of its ongoing criminal investigation, more than 170 interviews had been conducted, including with family members of the pilots and crew.[163][164] Investigators seized financial records for all 12 crew members, including bank statements, credit card bills and mortgage documents.[165] The preliminary report issued by Malaysia in March 2015 states that there was "no evidence of recent or imminent significant financial transactions carried out"[39]:20 by any of the pilots or crew and that analysis of the behaviour of the pilots on CCTV showed "no significant behavioural changes".[39]:21

Shortly after Flight 370's disappearance, media reports revealed that Captain Zaharie Ahmad Shah's wife and three children moved out of his house the day before the disappearance; and a friend claimed that Captain Shah was seeing another woman and Shah's relationship with her was also in trouble.[165][166][167] Claims of domestic problems have been denied by Shah's family.[168] A fellow pilot and long-time associate of Shah stated the Captain was "terribly upset"[169] that his marriage was falling apart.[166][167] Police were also investigating reports that Shah received a two-minute phone call prior to the flight's departure from an unidentified woman using a mobile phone number obtained with a false identity.[165] Furthermore, Captain Shah was also a supporter of Malaysian opposition politician Anwar Ibrahim, who was sentenced to jail on 7 March after an earlier acquittal on sodomy charges was overturned in a move viewed as politically motivated.[170]

On 23 June, an official Malaysian police investigation into the disappearance of Flight 370 identified the Captain as the prime suspect if it is proven human intervention was involved.[30] Contradicting an earlier statement about data from Shah's flight simulator, The Sunday Times reported that among deleted flight paths performed on the flight simulator investigators found a flight path into the Southern Ocean where a simulated landing was made on an island with a small runway.[168][171][172] Investigators noted strange behaviour by Shah from conducting 170 interviews—namely, that the Captain had made no social or professional plans for after 8 March, when Flight 370 disappeared.[172] News reports about the Captain's lack of social plans and flight simulator exercises cite results of the police enquiry into the pilots, which have been shared with some of the investigation team but have not been released publicly.[172]

Investigators believe someone in the cockpit of Flight 370 re-programmed the aircraft's autopilot before it travelled south across the Indian Ocean, raising further suspicion the disappearance was caused by the Captain or First Officer.[173] A hijacking by a pilot would not be without precedent, for example less than three weeks before Flight 370 disappeared—on 17 February 2014—Ethiopian Airlines Flight 702 was hijacked when the co-pilot locked the captain out of the cabin and diverted the aircraft to seek asylum in Switzerland.[174]

On 17 March, MAS chief executive, Ahmad Jauhari Yahya, indicated that the aircraft was carrying only three to four tonnes/tons of mangosteens and said that nothing it transported was dangerous.[175][176][177] Three days later, he confirmed that potentially flammable batteries, identified as lithium-ion,[178] were on board, adding that all cargo was "packed as recommended by the ICAO,"[179] checked several times, and deemed to meet regulations.[179][180][181] The cargo manifest released on 1 May[182] had revealed two air waybills (AWBs) for lithium-ion batteries with a total consignment weight of 221 kg. Three other AWBs weighing 2,232 kg were declared as radio accessories and chargers, but an MAS representative said he was not permitted to provide additional information.[183] Khalid Abu Bakar, Malaysia's Police Inspector-General, said that the provenance and destination of all cargo, including the mangosteens and in-flight meals, were being investigated to rule out sabotage as a cause.[184]

On 9 March 2014, members of the Chinese news media received an open letter that claimed to be from the leader of the Chinese Martyrs Brigade, a previously unknown group. The letter claimed that the loss of Flight 370 was in retaliation for the Chinese government's response to the knife attacks at Kunming railway station on 1 March 2014 and part of the wider separatist campaign against Chinese control over Xinjiang province. The letter also listed unspecified grievances against the Malaysian government. The letter's claim was dismissed as fraudulent based on its lack of detail regarding the fate of Flight 370 and the fact that the name "Chinese Martyrs Brigade" appeared inconsistent with Uyghur separatist groups which describe themselves as "East Turkestan" and "Islamic" rather than "Chinese".[185][186]

Public communication from Malaysian officials regarding the loss of the flight was initially beset with confusion.[l] The Malaysian government and the airline released imprecise, incomplete, and sometimes inaccurate information, with civilian officials sometimes contradicting military leaders.[199] Malaysian officials were criticised for such persistent release of contradictory information, most notably regarding the last point and time of contact with the aircraft.[200]

Although Malaysia's acting Transport Minister Hishammuddin Hussein, who is also the country's Defence Minister, denied the existence of problems between the participating countries, academics said that because of regional conflicts, there were genuine trust issues involved in co-operation and sharing intelligence, and that these were hampering the search.[201][202] International relations experts said entrenched rivalries over sovereignty, security, intelligence, and national interests made meaningful multilateral co-operation very difficult.[201][202] A Chinese academic made the observation that the parties were searching independently, thus it was not a multilateral search effort.[202]The Guardian noted the Vietnamese permission given for Chinese aircraft to overfly its airspace as a positive sign of co-operation.[202] Vietnam temporarily scaled back its search operations after the country's Deputy Transport Minister cited a lack of communication from Malaysian officials despite requests for more information.[203] China, through the official Xinhua News Agency, said that the Malaysian government ought to take charge and conduct the operation with greater transparency, a point echoed by the Chinese Foreign Ministry days later.[201][204]

Malaysia had initially declined to release raw data from its military radar, deeming the information "too sensitive,"[201] but later acceded.[201][202] Defence experts suggested that giving others access to radar information could be sensitive on a military level. As an example: "The rate at which they can take the picture can also reveal how good the radar system is."[201] One suggested that some countries could already have had radar data on the aircraft but were reluctant to share any information that could potentially reveal their defence capabilities and compromise their own security.[201] Similarly, submarines patrolling the South China Sea might have information in the event of a water impact, and sharing such information could reveal their locations and listening capabilities.[205]

Criticism was also levelled at the delay of the search efforts. On 11 March, three days after the aircraft disappeared, British satellite company Inmarsat had provided officials (or its partner, SITA) with data suggesting the aircraft was nowhere near the areas in the Gulf of Thailand and the South China Sea being searched at that time; and may have diverted its course through a southern or northern corridor. This information was only publicly acknowledged and released by Najib on 15 March in a press conference.[65][206] Explaining why information about satellite signals had not been made available earlier, Malaysia Airlines said that the raw satellite signals needed to be verified and analysed "so that their significance could be properly understood" before it could publicly confirm their existence.[207] Hishammuddin said Malaysian and US investigators had immediately discussed the Inmarsat data upon receiving them on 12 March, and on two occasions, both groups agreed that it needed further processing and sent the data to the US twice for this purpose. Data analysis was completed on 14 March: by then, the AAIB had independently arrived at the same conclusion.[208]

A month after the disappearance, Malaysia Airlines' chief executive Ahmad Jauhari Yahya acknowledged that ticket sales had declined but failed to provide specific details. This may partially result from the suspension of the airline's advertisement campaigns following the disappearance. Ahmad stated in an interview with the Wall Street Journal that the airline's "primary focus...is that we do take care of the families in terms of their emotional needs and also their financial needs. It is important that we provide answers for them. It is important that the world has answers, as well."[209] In further remarks, Ahmad said he was not sure when the airline could start repairing its image, but that the airline was adequately insured to cover the financial loss stemming from Flight 370's disappearance.[209][210] In China, where the majority of passengers were from, bookings on Malaysia Airlines were down 60 percent in March.[211]

Malaysia Airlines retired the Flight 370 (MH370) flight number and replaced it with Flight 318 (MH318) beginning 14 March. This follows a common practice among airlines to rename flights following notorious accidents.[212][213] The flight—Malaysia Airline's second daily flight to Beijing—was later suspended beginning 2 May; according to insiders, this was due to lack of demand.[42][214]

Malaysia Airlines was given US$110 million from insurers in March 2014 to cover initial payments to passengers' families and the search effort.[215] In May, remarks from lead reinsurer of the flight, Allianz, indicated the insured market loss on Flight 370, including the search, was about US$350 million.[216][217]

The airline was criticised on social media for gaffes made during advertisements. In September 2014, the airline launched a contest "My Ultimate Bucket List" in Australia and New Zealand. Since a bucket list is a list of goals to accomplish before you die, many found it very distasteful for an airline which lost 537 people killed and missing in the previous six months.[218] In November 2014, the airline tweeted "Want to go somewhere, but don't know where? Our Year-End Specials might just help! #keepflying"; the airline removed it and tweeted an apology after the public drew parallels to Flight 370.[219][220]

At the time of Flight 370's disappearance, Malaysia Airlines was struggling to cut costs to compete with a wave of new, low-cost carriers in the region. In the previous three years, Malaysia Airlines had booked losses of: RM1.17 billion (US$356 million) in 2013, RM433 million in 2012, and RM2.5 billion in 2011.[209] Malaysia Airlines lost RM443.4 million (US$137.4 million) in the first quarter of 2014 (January–March).[210] The second quarter—the first full quarter in the aftermath of Flight 370's disappearance—saw a loss of RM307.04 million (US$97.6 million), which represented a 75 percent increase over losses from the second-quarter of 2013.[221] Industry analysts expect Malaysia Airlines to lose further market share and face a challenging environment to stand out from competitors while addressing their financial plight.[209] The company's stock, down as much as 20 percent following the disappearance of Flight 370, had fallen 80 percent over the previous five years, which contrasts with a rise in the Malaysian stock market of about 80 percent over the same period.[211]

Many analysts and the media suggested that Malaysia Airlines would need to rebrand and repair its image and/or require government assistance to return to profitability.[222][223][224][225][226] The loss of Flight 17 in July greatly exacerbated Malaysia Airline's woes. The combined effect on consumer confidence of the loss of Flights 370 and 17 and the airline's poor financial performance led Khazanah Nasional—the majority shareholder (69.37 percent)[227] and a Malaysian state-run investment arm—to announce on 8 August its plan to purchase the remainder of the airline, thereby renationalising it.[228][229][230]

Lack of evidence in determining the cause of Flight 370's disappearance, indeed even physical evidence that the aircraft crashed, raises many issues regarding responsibility for the accident and payments made by insurance agencies.[231] Under the Montreal Convention, it is the carrier's responsibility to prove lack of fault in an accident and each passenger's next-of-kin are automatically entitled, regardless of fault, to a payment of approximately US$175,000[m] from the airline's insurance company—a total of nearly US$40 million for the 227 passengers on board.[231]

Malaysia Airlines would still be vulnerable to civil lawsuits from passengers' families.[231] Compensation awarded during or settled out-of-court during civil trials will likely vary widely among passengers based on country of the court. An American court could likely award upwards of US$8–10 million, while Chinese courts would likely award a small fraction of that.[232][233][234] Despite the announcement that Flight 370 ended in the southern Indian Ocean, it was not until 29 January 2015 that the Malaysian government officially declared Flight 370 an accident with no survivors, a move that would allow compensation claims to be made.[235] The first lawsuit related to the disappearance was filed in October 2014–before Flight 370 was declared an accident–on behalf of two Malaysian boys whose father was a passenger,[n] for negligence in failing to contact the aircraft soon after it was lost and for breach of contract for failing to bring the passenger to his destination.[238]

Malaysian Airlines offered ex gratia condolence payments soon after the disappearance. In China, families of passengers were offered ¥31,000 (about US$5,000) "comfort money";[239] but some families rejected the offer.[240] It was also reported that Malaysian relatives only received $2,000.[240] In June, Malaysia's deputy Foreign Minister Hamzah Zainuddin said that families of seven passengers received $50,000 advance compensation from Malaysia Airlines,[241] but that full payout would come after the aircraft is found or officially declared lost[242] (which later occurred in January 2015).[235]

Questions and criticisms were raised by air force experts and the Malaysian opposition about the current state of Malaysia's air force and radar capabilities. The failure of the Royal Malaysian Air Force to identify and respond to an unidentified aircraft (later determined to be Flight 370) flying through Malaysian airspace has been criticised by many.[243][244][245][246] The Malaysian military became aware of the unidentified flight only after reviewing radar recordings several hours after Flight 370's disappearance.[245] Not only was the failure to recognise and react to the unidentified aircraft a security blunder, it was also a missed opportunity to intercept Flight 370 and prevent the time-consuming and expensive search operation.[245][246]

Malaysian Prime Minister Najib Razak responded to criticism of his government in an opinion piece published in the The Wall Street Journal:

Without physical evidence, or a clear explanation for why this happened, peoples' attention has naturally focused on the authorities—and Malaysia has borne the brunt of the criticism. In the passage of time, I believe Malaysia will be credited for doing its best under near-impossible circumstances. It is no small feat for a country the size of ours to overcome diplomatic and military sensitivities and bring 26 different countries together to conduct one of the world's largest peacetime search operations. But we didn't get everything right...the response time should and will be investigated...I pledge that Malaysia will keep searching for the plane for as long as it takes.

In the opinion piece, Najib goes on to emphasise the need for the aviation industry to "not only learn the lessons of MH370 but implement them," saying in closing that "the world learned from [Air France Flight 447] but didn't act. The same mistake must not be made again."[247]

Opposition leader Anwar Ibrahim strongly criticised the Malaysian government regarding its response to Flight 370's disappearance and the military's response when Flight 370 turned back over the Malay Peninsula; he has called for an international committee to take charge of the investigation "to save the image of the country and to save the country."[248] Malaysian authorities have accused Anwar—who was jailed on contentious charges the day before Flight 370 disappeared—of politicising the crisis. Flight 370's captain was a supporter of Anwar and the two knew each other.[248]

Malaysia's Defence and Transport Minister Hishammuddin Hussein—a central figure in the search and investigation of Flight 370 and active on Twitter—was criticised for responding/retweeting a tweet by a Malaysian journalist: "Right u are:) @IsmailAmsyar: #MH370 is a blessing in disguise 4 all of us. I understand now d beauty of unity & sweetness of having each other."[249] The remarks were viewed as insensitive to the victims' families. Both tweets were removed.[249][250] Questioned why Malaysia did not scramble fighter jets to intercept the aircraft as it tracked back across the Malay Peninsula, he noted that it was deemed a commercial aircraft and was not hostile, remarking: "If you're not going to shoot it down, what's the point of sending [a fighter jet] up?"[251]

The poor response to the crisis and lack of transparency in the response has brought attention to the state of media in Malaysia. After decades of having tight control of media, during which government officials were accustomed to passing over issues without scrutiny or accountability, Malaysia was suddenly thrust to the forefront of global media and unable to adjust to demands for transparency. Confronted by a foreign journalist about the slow response and conflicting information, Defence and Transport Minister Hishammuddin Hussein responded that he had received "a lot of feedback saying we’ve been very responsible in our actions...it’s very irresponsible of you to say that."[252]

Chinese Deputy Foreign Minister Xie Hangsheng reacted sceptically to the conclusion by the Malaysian government that the aircraft had gone down with no survivors, demanding "all the relevant information and evidence about the satellite data analysis" and said that the Malaysian government must "finish all the work including search and rescue."[68][253] The following day, 25 March, Chinese president Xi Jinping sent a special envoy to Kuala Lumpur to consult with the Malaysian government over the missing aircraft;[254]

On 25 March, around two hundred family members of the Chinese passengers protested outside the Malaysian embassy in Beijing.[255][256] Relatives who had arrived in Kuala Lumpur after the announcement continued with their protest, accusing Malaysia of hiding the truth and harbouring the murderer. They also wanted an apology for the Malaysian government's poor initial handling of the disaster and its "premature" conclusion of loss, drawn without physical evidence.[257] An op-ed for China Daily said that Malaysia was not wholly to be blamed for its poor handling of such a "bizarre"[258] and "unprecedented crisis,"[258] and appealed to Chinese people not to allow emotions to prevail over evidence and rationality.[258] The Chinese ambassador to Malaysia defended the Malaysian government's response, stating that the relatives' "radical and irresponsible opinions do not represent the views of Chinese people and the Chinese government".[259] The ambassador also strongly criticised Western media for having "published false news, stoked conflict and even spread rumours"[184] to the detriment of relatives and of Sino–Malaysian relations.[184] On the other hand, a US Department of Defense official criticised China for what he perceived as providing apparently false leads that detracted from the search effort and wasted time and resources.[260][261]

Some Chinese have boycotted all things Malaysian, including vacations and singers, in protest of Malaysia's handling of the Flight 370 investigation.[262][263] Bookings on Malaysia Airlines from China, where the majority of passengers were from, were down 60 percent in March.[211] In late March, several major Chinese ticketing agencies—ELong, LY.com, Qunar and Mango—banned sale of airline tickets to Malaysia[262][264] and several large Chinese travel agencies reported a 50 percent drop in tourists compared to the same period the year before.[214] China is the third largest source of visitors for Malaysia, accounting for 1.79 million tourists.[214] One market analyst predicted a 20–40 percent drop in Chinese tourists to Malaysia, resulting in a loss of 4-8 billion yuan (RM2.1-4.2 billion; US$650 million-1.3 billion).[214][265]

The boycotts have largely been led or supported by celebrities.[214][266] Film star Chen Kun posted a message to Weibo—where he has 70 million followers—stating: "I...will start a boycott from my inner heart on any commercials and travel relating to Malaysia. This will last...until the Malaysian government takes down their clown-like mask and tells the truth."[214] The post was shared over 70,000 times and drew over 30,000 comments.[214] Over 337,000 people retweeted a tweet from TV host Meng Fei, which said "I’ve never been to Malaysia and I do not plan to go there in the future. If you feel the same, please retweet this message."[214]

The fact that, in a digitally-connected world, a modern aircraft could simply disappear has been met with surprise and disbelief by the public; and while changes in the aviation industry often take years to be implemented, airlines and air transport authorities have responded swiftly to take action on several measures to prevent a similar incident from occurring.[267][268][269][270]

The International Air Transport Association—an industry trade organisation representing over 240 airlines (representing 84 percent of global air traffic)—and the United Nation's civil aviation body—the International Civil Aviation Organization (ICAO)—are working on implementing new measures to track aircraft in flight in real time.[271] The IATA created a task force (which includes several outside stakeholders)[271] to define a minimum set of requirements that any tracking system must meet, allowing airlines to decide the best solution to track their aircraft. The IATA's task force plans to come up with several short-, medium-, and long-term solutions to ensure that information is provided in a timely manner to support search, rescue, and recovery activities in the wake of an aircraft accident.[272] The task force was expected to provide a report to the ICAO on 30 September 2014, but on that day said that the report would be delayed, citing the need for further clarification on some issues.[273][274] In December 2014, the IATA task force recommended that, within 12 months, airlines track commercial aircraft in no longer than 15-minute intervals, although it still has not released its report and full details of proposed changes. The IATA itself did not support the deadline, which it believes cannot be met by all airlines, but the proposed standard has the support of the ICAO. Although the ICAO can set standards, it has no legal authority and such standards must be adopted by member states.[37][38]

In May 2014, Inmarsat said it would offer its tracking service for free to all aircraft equipped with an Inmarsat satellite connection (which amounts to nearly all commercial airliners).[275] Inmarsat has also changed the time period for handshakes with their terminals from one hour to 15 minutes.[147]:2

There was a call for automated transponders after the 11 September 2001 terrorist attacks; no changes were made as aviation experts preferred flexible control, in case of malfunctions or electrical emergencies.[276] In the wake of Flight 370, the air transport industry is still resistant to the installation of automated transponders, which would likely entail significant costs. Pilots have also criticised changes of this kind, insisting on the need to cut power to equipment in the event of a fire. Nonetheless, new types of tamper-proof circuit breakers are being considered.[269]

Detection of the acoustic signal from the ULBs must be made below the thermocline and within a maximum range, under nominal conditions, of 2,000–3,000 m (1.2–1.9 mi). With a ULB battery life of 30-40 days, searching for the important flight recorders is very difficult without precise coordinates of the location the aircraft entered the water.

The frenzied search for the flight recorders in early April, due to the 30-day battery life of the underwater locator beacons (ULBs) attached to them, brought attention to the limitations of the ULBs.[o][277] Not only is the battery life of the ULBs limited, but the nominal distance at which the signal from the ULBs can be detected is 2,000–3,000 m (1.2–1.9 mi), up to 4,500 m (2.8 mi) under favourable conditions.[5]:11 Even if the flight recorders are located, the cockpit voice recorder memory has capacity to store only two hours of data, continuously recording over the oldest data. This length complies with regulations and it is usually only data from the last section of a flight that is needed to determine the cause of an accident. The events which caused Flight 370 to divert from its course and disappear happened more than two hours before the flight ended.[278] Given these limitations and the importance of the data stored on flight recorders, Flight 370 has brought attention to new technologies that enable the data stream to the ground.[279][280][281]

A call to increase the battery life of ULBs was made after the unsuccessful initial search in 2009 for the flight recorders on Air France Flight 447, which were not located until 2011. The ICAO did not make such a recommendation until 2014, with implementation by 2018.[280] The European Aviation Safety Agency has stated its new regulations require that the transmitting time of ULBs fitted to aircraft flight recorders must range from 30 to 90 days. The agency proposed a new underwater locator beacon with a larger transmitting range to be fitted to aircraft flying over oceans.[272]

In January 2015, the US NTSB cited Flight 370 and Air France Flight 447 when it issued eight safety recommendations[p] related to locating aircraft wreckage in remote or underwater locations and repeated recommendations for a crash-protected cockpit image recorder and tamper-resistant flight recorders and transponders.[282][283]

Flight 370 disappears after departing Kuala Lumpur at 00:41 MYT (16:41 UTC, 7 March). A search and rescue effort is launched in the South China Sea and Gulf of Thailand.[284]

10 March

Malaysia's military announces that Flight 370 may have turned back and flew west towards Malaysia. The search is expanded to include the Strait of Malacca.[74]

12 March

Malaysia announces that Flight 370 crossed the Malay Peninsula and was last spotted on military radar 200 nmi (370 km; 230 mi) northwest of Penang on Malaysia's west coast. The focus of the search is shifted to the Andaman Sea and Strait of Malacca.[54][285]

15 March

Officials announce that communications between Flight 370 and a communications satellite operated by Inmarsat indicate it continued to fly for several more hours and was along one of two corridors at the time of its last communication.[75][286]

18 March – 28 April

Aerial search of the southern Indian Ocean, west of Australia, is conducted.[5][287]

24 March

Prime Minister of Malaysia announces that Flight 370 is presumed to have gone down in the southern Indian Ocean; Malaysia Airlines states to families that it assumes "beyond reasonable doubt" there are no survivors.[288] The northern search corridor (northwest of Malaysia) and the northern half of the southern search corridor (the waters between Indonesia and Australia) are definitively ruled out.[289]

30 March

The Joint Agency Coordination Centre is created to co-ordinate the multinational search effort.[290]

2–14 April

An intense effort by several vessels and aircraft-deployed sonobuoys is made to detect underwater acoustic signals made by underwater locator beacons attached to the aircraft's data recorders. Several acoustic detections are made between 4–8 April.[5]

14 April – 28 May

A sonar survey of 860 km2 (330 sq mi) of seafloor near the 4–8 April acoustic detections is conducted, yielding nil debris.[5]

1 May

A preliminary report from Malaysia to the ICAO (dated 9 April 2014) is publicly released along with: copies of cargo manifest documents; audio recordings (and transcript) of communications between air traffic control and Flight 370; a log of actions taken by air traffic control (Kuala Lumpur ACC) in the hours after Flight 370 disappeared from their radar (01:38-06:14 MYT).[44]

27 May

The data logs of satellite communications between Flight 370 and Inmarsat are released, following criticism over the way this data had been analysed and scepticism of whether Flight 370 really ended in the southern Indian Ocean.[291]

Video tour of bathymetry data collected during the bathymetric survey.

May–December

A bathymetric survey is conducted in the region to be searched.

26 June

Plans for the next phase of the search (the "underwater search") are announced to the public in-depth for the first time and the Australian Transport Safety Bureau releases a report[5] detailing the previous search efforts, analysis of satellite communications, methodology used to determine the new search area.[292]

October–ongoing

The underwater search began on 6 October and is expected to last up to 12 months. The search is conducted in areas where the bathymetric survey has been completed.[293][294]

8 October

Officials announce that the priority area to be searched is further south of the area identified in the June ATSB report.[98] The ATSB releases a report (a supplement to the June report) that details the methodology behind refinements to the analysis of satellite communications.[47]

29 January 2015

The Malaysian government officially declares Flight 370 an accident, in accordance with Annexes 12 and 13 to the Chicago Convention, with no survivors.[1]

Several documentaries have been produced about the flight. The Smithsonian Channel aired a one-hour documentary about the flight on 6 April 2014, titled Malaysia 370: The Plane That Vanished.[303][304] The Discovery Channel broadcast a one-hour documentary about Flight 370 on 16 April 2014 titled Flight 370: The Missing Links.[305][306]

An episode of the television documentary series Horizon titled "Where is Flight MH370?" was broadcast on 17 June 2014 on BBC Two. The programme, narrated by Amanda Drew, documents how the aircraft disappeared, what experts believe happened to it, and how the search has unfolded. The programme also examines such new technologies as flight recorder streaming and Automatic dependent surveillance-broadcast (ADSB), which may help prevent similar disappearances in the future. It concludes by noting that Ocean Shield had spent two months searching 850 square kilometres (330 sq mi) of ocean, but that it had searched far to the north of the Inmarsat "hotspot" on the final arc, at approximately 28 degrees south, where the aircraft was most likely to have crashed.[307] On 8 October 2014, a modified version of the Horizon programme was broadcast in the US by PBS as an episode of Nova, titled "Why Planes Vanish", with a different narrator.[308][309][310]

The first fictional account of the mystery was Scott Maka's MH370: A Novella, published three months after the aircraft's disappearance.[311]

The aviation disaster documentary television series Mayday (also known as Air Crash Investigation or Air Emergency) produced an episode on the disaster, titled "Malaysia 370: What Happened?" In the UK, it aired on the first anniversary of Flight 370's disappearance, 8 March 2015.[312]

^ abNo human remains of Flight 370 passengers or crew have been located; survival in the area where Flight 370 is believed to have entered the ocean is unlikely and the Malaysian government believes all passengers and crew are dead.[1] Additional details in the "presumed loss" section.

^ abcAircraft altitude is given in feet above sea level and measured, at higher altitudes, by air pressure, which declines linearly as altitude above sea level increases. Using a standard sea level pressure and formula, the nominal altitude of a given air pressure can be determined—referred to as the "pressure altitude". A flight level is the pressure altitude in 100s of feet. For example, flight level 350 corresponds to an altitude where air pressure is 179 mmHg (23.9 kPa), which is nominally 35,000 ft (10,700 m) but does not indicate the true altitude.

^Responsibility for air traffic control is geographically partitioned, through international agreements, into flight information regions (FIRs). Although the airspace at the point where Flight 370 was lost is part of the Singapore FIR, the Kuala Lumpur ACC had been delegated responsibility to provide air traffic control services to aircraft in that part of its FIR.[43]:13

^Heights given by primary radar are actual altitudes, unlike the pressure altitudes provided by secondary radar.

^The aircraft is a Boeing 777-200ER (for Extended Range) model; Boeing assigns a unique customer code for each company that buys one of its aircraft, which is applied as an infix in the model number at the time the aircraft is built. The code for Malaysia Airlines is "H6", hence "777-2H6ER".[107]

^The timing of the log-on interrogation message is determined by an inactivity timer, which was set to one hour at the time Flight 370 disappeared (it was later reduced to 15 minutes).[5]:18

^Information released and reported publicly about SATCOM transmissions from Flight 370 have been inconsistent, especially the use of the terms "ping" and "handshake". It was initially reported as six "handshakes" or "pings" with one "partial handshake or ping" sent at 00:19 UTC by Flight 370, unprovoked by the ground station. The events listed may consist of several "transmissions" between the aircraft and ground station over the course of a few seconds. A readable copy of the ground station log of transmissions to and from Flight 370 is available here [1].

^Examples:
* Malaysia Airlines' chief executive, Ahmad Jauhari Yahya, initially said air traffic control was in contact with the aircraft two hours into the flight when in fact the last contact with air traffic control was less than an hour after takeoff.[187]
* Malaysian authorities initially reported that four passengers used stolen passports to board the aircraft before settling on two: one Italian and one Austrian.[188]
* Malaysia abruptly widened the search area to the west on 9 March, and only later explained that military radar had detected the aircraft turning back.[188] This was later formally denied by Rodzali Daud.[189]
* Malaysian authorities visited the homes of pilot Zaharie and co-pilot Fariq on 15 March, during which they took away a flight simulator belonging to Zaharie. Malaysian police chief Khalid Abu Bakar said this was the first police visit to those homes. On 17 March, the government contradicted this by saying police first visited the pilots' homes on the day following the flight's disappearance,[190] although this had been previously denied.[191]
* On 16 March, Malaysia's acting transport minister contradicted the prime minister's account on the timing of the final data and communications received. Najib Razak had said that the ACARS system was switched off at 01:07. On 17 March, Malaysian officials said that the system was switched off sometime between 01:07, time of the last ACARS transmission, and 01:37, time of the next expected transmission.[192][193]
* Three days after saying that the aircraft was not transporting anything hazardous, Malaysia Airlines' chief executive Ahmad said that potentially dangerous lithium batteries were on board.[176][178]
* MAS chief executive initially claimed that the last voice communication from the aircraft was, "all right, good night", with the lack of a call sign fuelling speculation that the flight may have been hijacked.[63][194][195] Three weeks later Malaysian authorities published the transcript that indicated the last words were "Good night Malaysian three seven zero".[48][196][197][198]

^In March 2014, a petition for discovery was filed in a US court by a law firm, not representing relatives of families, against Boeing and Malaysia Airlines. It sought to obtain the names of manufacturers of aircraft parts along with maintenance records. It was reported in the media as a lawsuit or that Malaysia Airlines was being sued.[236][237]

^Regulations require ULBs to transmit a minimum of 30 days. The ULBs on the flight recorders on Flight 370 had a minimum 30-day battery life after immersion. The ULB manufacturer predicted the maximum battery life was 40 days after immersion.[5]:11

^ abWatson, Ivan (29 April 2014). "MH370: Plane audio recording played in public for first time to Chinese families". CNN. Retrieved 14 July 2014. "At 2:03 a.m. local time on March 8, the operational dispatch center of Malaysia Airlines sent a message to the cockpit instructing the pilot to contact ground control in Vietnam, said Sayid Ruzaimi Syed Aris, an official with Malaysia's aviation authority...MH370 did not respond to the message...'At 7:13,' Sayid said, Malaysia Airlines tried to 'make a voice call to the aircraft, but no pickup.'

^"MH370 Operational Search Update— 14 January 2015". JACC. 14 January 2015. Retrieved 2 February 2015. Fugro Supporter is expected to arrive in the search area and commence search activities in late January. Fugro Supporter has been equipped with a Kongsberg HUGIN 4500 autonomous underwater vehicle (AUV). The AUV will be used to scan those portions of the search area that cannot be searched effectively by the equipment on the other search vessels.

MH 370 Preliminary Report – Preliminary report issued by the Malaysia Ministry of Transport. Dated 9 April 2014 and released publicly on 1 May 2014.

MH370 – Definition of Underwater Search Areas – Report by the Australian Transport Safety Bureau, released 26 June 2014, and the most comprehensive report on Flight 370 publicly released at that time. The report focuses on defining the search area for the fifth phase, but in doing so provides a comprehensive overview/examination of satellite data, the failed searches, and possible "end-of-flight scenarios".